Method for reducing exhaust carbon dioxide

• US 20050036932A1
• Filed: 07/22/2004
• Published: 02/17/2005
• Est. Priority Date: 10/29/1998
• Status: Abandoned Application

• Current Assignee: JFE Steel Corporation (JFE Holdings Incorporated)
• Original Assignee: NKK Corporation (JFE Holdings Incorporated)
• Inventors: Kato, Makoto, Takahashi, Tatsuhito, Tanabe, Haruyoshi, Isoo, Tsuneo
• Application Number:
  US10/898,491
• Publication Number:
  US 20050036932A1
• Time in Patent Office: Days
• US Class Current: 423/432
• CPC Class Codes: A01G 33/00 Cultivation of seaweed or algae
• CPC Class Codes: B01D 2251/404 of calcium
• CPC Class Codes: B01D 2251/604 Hydroxides
• CPC Class Codes: B01D 2257/504 Carbon dioxide
• CPC Class Codes: B01D 53/62 Carbon oxides
• CPC Class Codes: C01F 11/18 Carbonates
• CPC Class Codes: Y02A 20/402 River restoration
• CPC Class Codes: Y02C 20/40 of CO2
• CPC Class Codes: Y02P 20/151 Reduction of greenhouse gas [GHG] emissions, e.g. CO2
• CPC Class Codes: Y02P 60/20 Reduction of greenhouse gas [GHG] emissions in agriculture, e.g. CO2

Abstract

A method for effectively absorbing and removing CO₂ in an exhaust gas generated during an industrial process for reducing the amount of CO₂ that is exhausted into the atmosphere. The exhaust gas containing CO₂ is blown into an agglomerate of solid particles containing CaO and/or Ca(OH)₂ so that the CO₂ is in contact with the agglomerate for fixing the CO₂ in the exhaust gas as CaCO₃, thereby reducing the CO₂ concentration in the exhaust gas. Preferably, the solid particles contain water, and more preferably, the solid particles contain surface adhesive water.

Claims

1. A method for reducing an exhaust carbon dioxide comprising:

preparing agglomerates of solid particles containing at least one compound selected from the group consisting of CaO and Ca(OH)₂;

contacting an exhaust gas containing CO₂ with the agglomerates of the solid particles in a reaction chamber, the solid particles having a film of adhesive water on a surface of the solid particles; and

fixing CO₂ in the exhaust gas as CaCO₃ in the solid particles to reduce CO₂ in the exhaust gas.

2. The method according to claim 1, wherein the agglomerates of the solid particles are obtained by pulverizing materials containing CaO and/or Ca(OH)₂ into grain and/or rough grain.

3. The method according to claim 1, wherein the step of contacting the exhaust gas comprises contacting an exhaust gas containing CO₂ with the agglomerates of the solid particles by blowing the exhaust gas into the agglomerates of the solid particles.

4. The method according to claim 3, wherein the exhaust gas containing CO₂ is blown into the agglomerates of the solid particles from one direction.

5. The method according to claim 1, wherein the water content in the agglomerates of the solid particles is from 3 wt. % to 20 wt. %.

6. The method according to claim 1, wherein a grain size of the solid particles is substantially 5 mm or less.

7. The method according to claim 1, wherein the exhaust gas introduced into the reaction chamber is at a temperature corresponding to the boiling point of water or lower, within the reaction chamber.

8. The method according to claim 1, wherein the reaction chamber is at a temperature corresponding to the boiling point of water or lower.

9. The method according to claim 1, wherein a temperature of the agglomerates of the solid particles is at a temperature corresponding to the boiling point of water or lower, within the reaction chamber.

10. The method according to claim 1, wherein the step of contacting the exhaust gas containing CO₂ with the agglomerates of the solid particles comprises contacting a pressurized exhaust gas with the agglomerates of the solid particles.

11. The method according to claim 1, further comprising saturating H₂O in the exhaust gas, prior to contacting the exhaust gas with the agglomerates of the solid particles.

12. The method according to claim 1, wherein the water content in the agglomerates of the solid particles is a range of from 3 to 20 wt. %, and the exhaust gas is blown into the agglomerates of the solid particles, to contact the exhaust gas with the agglomerates of the solid particles.

13. The method according to claim 12, wherein the exhaust gas introduced into the reaction chamber is at a temperature corresponding to the boiling point of water or lower, within the reaction chamber, the reaction chamber is at a temperature corresponding to the boiling point of water or lower, and the agglomerates of the solid particles to be contacted with the exhaust gas is at a temperature corresponding to the boiling point of water or lower, within the reaction chamber.

14. The method according to claim 13, further comprising saturating H₂O in the exhaust gas prior to contacting the exhaust gas with the agglomerates of the solid particles.

15. The method according to claim 1, wherein the agglomerates of the solid particles are at least one material selected from the group consisting of a slag generated in an iron and steel making process and a concrete.

16. The method according to claim 1, wherein the solid particles of the agglomerates are at least one material selected from the group consisting of a slag generated in an iron and steel making process and a concrete.

17. The method according to claim 1, wherein the agglomerates of the solid particles are at least one material selected from the group consisting of a slag generated in an iron-steel making process, a concrete, a mortar, a glass, an alumna cement and a CaO containing refractory.

18. A method of creating a seaweed bed comprising:

temporarily immersing a heavy material in an existing seaweed bed so that marine algae adhere and grow on a surface of the material;

recovering the heavy material and transporting the heavy material as a seed material in a place for creating the seaweed bed; and

arranging an adhering material for adhering the marine algae around the seed material so that the marine algae on the seed material is proliferated onto another seed material.